It has been found that in certain transportation systems, such as in modern transportation systems, such as in railway and/or mass or rapid transit operations, there is a need for providing improved wheel spin sensing and detecting apparatus for more accurately determining the actual speed and the exact distance that the railway train has traveled as it proceeds along its route of travel. The mandated use of event recorders on railroad lead locomotives and on any self-powered transit vehicle has made it necessary to provide an accurate record of speed, distance, time, direction, etc., in case of an accident or equipment failure. Previously, the conventional speedometer and odometer circuits were generally connected to a single axle of a multiple-axle railway vehicle. If this selected axle is spinning, there is a significant chance an error will occur in the speed and distance records. That is, the speed signal of the spin wheel being read is much higher than the actual velocity of the accelerating train so that the recorded data does not reflect the exact speed and distance of travel. Thus, the recorded data was unreliable and was of little use in aiding accident analysis and in monitoring engineers' performances or in observing the operation of the equipment. Hence, the usefulness of event recorders to provide data that is exempt from prejudice, free from errors of human observances and untainted from the possibility of self-interest is compromised by equipment that simply employs a single-axle sensor for detecting wheel spin.